MicroMark MicroMill - Review

[mtaylor]

This tool is full of pluses and minuses.   Relatively inexpensive (for a mill), lightweight, small, has reasonable power for its size.  All controls are easily used and seem very precise.  Two downsides.. the first is that accessories relatively hard to come by.  Everyone sells accessories for the larger "mini" size, the R8 from MM or Sherline type. The other is the RPM is limited to 2800.

 

I was able to rework the pulleys so it turns at about 12,000 rpm.  But I have to monitor the bearing temperature and I killed the warranty with this mod.  I've also had to adapt vises and hold pieces to fit as they are all for the larger mills.  This also, not a production type tool.  Not designed to run 8 hours a day even before the RPM boost.

 

All in all, not a bad value for the money.  However, given what I know now, I go for the mini type available from MicroMark, Harbor Freight and Sherline.  Probably the Sherline with their RPM kit.

 

 

 

[wefalck]

I was able to rework the pulleys so it turns at about 12,000 rpm. 

Are you sure the bearings are rated for such a speed ?

 

wefalck

[mtaylor]

Wefalck,

 

They're not rated for that speed, that's why I have monitor for heating.  The tech I talked to, thought they would be ok if I had been using the mill and the bearings were run in.  However, I'm only runing it at speeds above 3000 rpm in short bursts at this point.

[JPett]

Ahoy Mark

 

I noticed you did not mention the Proxxon MF 70 which has a continuously variable speed from 5,000 - 20,000 rpm and sells for around 400. I ask only because this is on my list

 

http://www.proxxon.com/eng/html/27110.php

[bbrockel]

JPett, it wasn't mentioned because the title of the thread is MICROMARK MINIMILL REVIEW, not Proxxon review.

[Jim Lad]

Gentlemen, stay cool and be nice to each other!!

 

John

[mtaylor]

JP... I didn't mention it because for my needs it's even smaller than the mill I have.  I would still go for a bigger (physically) model of mill. 

The Proxxon seems to only come in 220/240 VAC, the motor is not rated as high as the Micromark.  The X-Y Table is smaller.

Your needs may vary and the smaller might work.  Thus, I only mentioned what "I" would go for.

[JPett]

Thanks Mark

 

I did not realize the Proxxon was so small. I do like the speed as compared to the other models. My research on mills confirmed that for smaller parts a higher speed was preferred; I also noticed B.E. uses one.

 

Hummm

 

It is available in 110V too

 

I really need to hit that lottery

[wefalck]

The spindle speed has to be a function of cutter diameter and material to be worked. For a cutter of say of 50 mm diameter and working steel, you would go down to a few hundred RPM. Conversely, with a small router in wood you need probably 10k or 20k RPM to achieve a clean cut.

 

wefalck

[mtaylor]

Janos,

You are probably correct.  The strange thing is Sherline, etc. all call their devices "mills" and all have <3000 rpm from the factory.  Strange indeed.

 

Wefalck,

That's true and the big reason I had to increase the spindle speed.

[wefalck]

Sherline et al. call their mills because they are mills. As I said, it has nothing to do with spindle speeds, only with the geometric arrangement of the machine tool - and the design of the spindle: a drilling machine is designed for axial forces, a milling machine for radial forces and axial forces on the spindle. The table of (co-odinate) drilling machines may also not be designed for being moved under load, i.e. for milling, though using it for light milling might be ok.

 

wefalck

[mtaylor]

I just noticed that MicroMark no longer carries this mill...  so when mine dies, I'll get to upgrade.   

[Q A's Revenge]

The problem buying a milling machine to cut wood is that with a few notable exceptions they are generally designed to cut metal. As a result the speed range is often around 200 - 2800 rpm, ideal for cutting metal. One of my favourite tools is the fly cutter. It's great for squaring up stock on the mill and has a sweep up to nearly 3 inches. I normally run this at a couple of hundred rpm.

 

 

As you can see from this chart though, 2800 rpm is still quite low even for cutting some metals. Having said that, these things are a guide and you can normally get good results running cutters a lot slower provided you don't feed them into the work too quickly. The speed range on my mill is 160 - 2540 and I've not had any problems using a 1/16" cutter in it. I have cut wood on my mill but the smallest cutter I used was around 1/2" and this worked ok in hardwood at the maximum speed but obviously not as clean as using a router.

 

 

Having said all that, small milling machines are not expected to remove large amounts of metal with large cutters so the speed range is often higher than you would expect to see on larger machines. If you only want to cut wood, and especially with very small cutters then look for the highest speed range you can get.

[michael mott]

Mark, I think that you would do well to get the largest mill you can afford, Wefalk's comments about the differences in mills and drills is good.The thing that I find the most limiting usually is the size of the table and its travel distances.

 

Q That is a nice little chart

 

Michael

[Maury S]

You can have the belt-gears changed to speed up (2 x) the mill rpm.  I did that on the big MicroMark mill with a package from the Little Machine Shop.  It includes the gears and beefed-up bearings.  Beware...voids the mft warranty.  I had to have a machine shop do the bearing replacement. 

Maury

[mtaylor]

Michael,

 

When the mill I have dies, you can bet I'll be upgrading...

 

Maury,

 

Oh yes.. I made my own mod to this mill to hit about 12,000 rpm at the tool.   That is a definite "must" upgrade for any mill we use to work with wood, IMO.